The wife of an alleged extremist is due to appear in court accused of helping her husband buy a knife in a plot to carry out an attack.
Ummariyat Mirza, 21, bought a blade and carried out research to put his plan into action, police say.
His wife Madihah Taheer, also 21, is accused of supporting him and allegedly handed over her bank details for him to buy a knife.
Taheer, from St Agathas Road, Birmingham, was arrested by the West Midlands counter-terrorism unit in the city on Monday and is charged with assisting Mirza to commit acts of terrorism.
She was remanded in custody and is due to appear at Westminster Magistrates' Court.
Mirza, of the same address, was arrested on March 29 and appeared in court on April 6 charged with preparing to commit an act of terrorism.
He is also charged with possessing bomb-making guide the Anarchist Cookbook and an extremist document called the Mujahideen Poisons handbook.
His sister Zainub Mirza, 23, from Eastfield Road, Bordesley Green, appeared alongside him in court, charged with sending Islamic State propaganda videos to others.
It is alleged she sent the extremist material, including a picture of a man holding two severed heads, to encourage terror attacks.
The siblings previously appeared at Westminster Magistrates' Court and are due to appear on April 28 at the Old Bailey.